US patent application 2014/0045736 teaches an antioxidant and antiwear additive for lubricating compositions comprising an aromatic amine antioxidant in combination with an ashless dithiocarbamate. While alkylated phenyl-α-naphthylamine (APANA) is an aromatic amine antioxidant, no specific disclosure of this particular compound is suggested. Rather, only octylated or nonylated diphenylamine are specifically discussed.
U.S. Pat. No. 6,743,759 teaches the combination of ADPA derivative of tolutriazole and methylenebis(dibutyldithiocarbamate). Optional components include antioxidants, and APANA is among the list of literally dozens of possible antioxidant compounds, with no particular preference except for nonylated diphenylamine. No suggestion is made that the use of APANA in particular will provide a further synergy when used with the primary two-component composition of the reference.